ASCR Science Highlightshttp://science.energy.gov/ascr/highlights/The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, providing more than 40 percent of total funding for this vital area of national importance. It oversees - and is the principal federal funding agency of - the Nation's research programs in high-energy physics, nuclear physics, and fusion energy sciences.en{5E87B9BD-D921-4FAB-B878-B2C82EC57697}http://science.energy.gov/ascr/highlights/2015/fes-2015-07-a/Double, Double Toil and Trouble: Tungsten Burn and Helium Bubbles<img src='/~/media/142621DB8F8C4EB1869FC955BC84D21D.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>New models reveal the impact of competing processes on helium bubble formation in plasma-exposed tungsten.Thu, 09 Jul 2015 12:29:46 -0400<p>Accelerated molecular dynamics was used to extend the time scale of atomistic simulations beyond conventional molecular dynamics while retaining full atomic fidelity. The deployment of these methods on the Titan supercomputer at Oak Ridge Leadership Computing Facility at Oak Ridge National Laboratory has enabled, for the first time, the simulation of the evolution of helium bubbles at helium implantation rates appropriate for the conditions at ITER. The simulations revealed that at high helium implantation rates, the tungsten atoms surrounding the bubble simply did not have time to respond to the accumulated pressure, resulting in highly over-pressurized bubbles that grew to large sizes and burst violently upon reaching the material surface. In contrast, once the helium implantation rate was reduced to more reasonable values, possible via the use of accelerated molecular dynamics methods on up to 50% of the supercomputer, the time between the arrivals of helium atoms to the bubble was much longer, allowing the tungsten atoms to respond to the pressure within the bubble. In particular, tungsten interstitial atoms at the surface of the bubble can diffuse around it and feel the nearby surface. This interaction leads to bubble growth directed toward the surface and results in a smaller bubble size when it ultimately bursts. These results highlight the importance of accounting for all relevant kinetic processes and how these kinetic processes enhance the interaction of, in this case, the helium bubble with the local microstructure. The results further have consequences for the nucleation of surface morphology on the tungsten, which is ultimately the source of fuzz, a nanostructured &ldquo;steel wool&rdquo;-like structure that causes significant degradation in performance of the material.</p>{962EBAA6-D8AF-4EA3-836F-AA129C994190}http://science.energy.gov/ascr/highlights/2015/ascr-2015-07-a/Mystery Object in Ultracold Superfluids Identified in New Simulation<img src='/~/media/EB6AB87E16E544CDBDCBBED2E79E53B1.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Computational algorithms show whirlpools, not disks, form and dissipate on fluid’s surface.Thu, 09 Jul 2015 15:18:19 -0400<p>Experiments with ultracold superfluids, specifically Fermi gases, allow scientists to investigate quantum mechanical principles central to our understanding of the physical world. Researchers developed computational algorithms that consider the complex physics of Fermi gases. The new codes can account for instabilities, including dissipation, a phenomenon through which vortices displace energy. By introducing small, experimentally unavoidable symmetry breaking, the new simulations show that the whirlpools or vortex rings rapidly decay into more stable vortex lines. The disc-like solitons that had been postulated were not present in the superfluid. Stable vortex rings were not present either.&nbsp; Indeed, the only stable defects were vortex lines. Recent experiments confirm that the simulations properly identified the defects. The findings also show that the numerical simulations can realistically simulate quantum mechanical phenomena in superfluids.</p>{35B44EBD-923E-44B2-BCF1-F2BC6E8B0C37}http://science.energy.gov/ascr/highlights/2015/bes-2015-03-a/Insulator-to-Metal Transition of Vanadium Dioxide<img src='/~/media/C6EE135B1155482FB26D7B09E66F7E45.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>New studies explain the transition, providing a quantitative picture of a 50-year-old mystery.Mon, 09 Mar 2015 16:54:23 -0400<p>Vanadium dioxide (VO<sub>2</sub>), a &ldquo;functional material&rdquo; that could be used in applications such as smart windows and ultrafast field effect transistors, exhibits an insulator to metal transition upon heating to just above room temperature. At the transition temperature, its electrical conductivity abruptly increases by a factor of 10,000 and the atomic lattice rearranges from a monoclinic to a tetragonal structure (see figure). A fundamental description of the physical and electronic properties during the transition in VO<sub>2</sub> has remained controversial for over 50 years. Researchers at Oak Ridge National Laboratory employed advanced neutron and x-ray scattering experiments at DOE user facilities, coupled with large-scale first-principles calculations with super computers, to determine the detailed mechanism for the transition. Their studies, published in <em>Nature</em>, revealed that the thermodynamic force driving the insulator-to-metal transition is dominated by the lattice vibrations (phonons) rather than electronic contributions. In addition, a direct, quantitative determination of the phonon dispersions was&nbsp;achieved, as well as a description of how changing occupancies in the atomic orbitals participate in the phase transition. The low-energy phonons were found to change the bonds between atoms (i.e., electron orbitals), allowing some electrons to travel freely at higher temperatures leading to a metallic state.&nbsp;This research demonstrates that anharmonic lattice dynamics play a critical role in controlling phase competition in metal oxides, and provides the complete physical model vital for the predictive design of new materials with unique properties.</p>{C7CEA7CB-D1AF-4A1A-BFC3-C67A3E206CF4}http://science.energy.gov/ascr/highlights/2015/bes-2015-03-d/Multimetal Nanoframes Improve Catalyst Performance<img src='/~/media/5685C7865424447EA6D8918E8F361FE9.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Concentrating noble-metal catalyst atoms on the surface of porous nano-frame alloys shows over thirty-fold increase in performance.Mon, 09 Mar 2015 16:54:25 -0400<p>Control of structure at the atomic level can precisely and effectively tune catalytic properties of materials, enabling enhancement of both activity and durability. A team of researchers from Argonne National Laboratory, Lawrence Berkeley National Laboratory, and the University of Wisconsin synthesized a highly active and durable class of electrocatalysts by exploiting the structural evolution of solid Pt-Ni bimetallic nanocrystals into porous cage-like structures or nanoframes. The material was synthesized by exploiting the structural evolution of platinum-nickel (Pt-Ni) bimetallic nanocrystals into cage-like structures with a self-assembled Pt skin structure on the interior and exterior surfaces. The starting material, crystalline PtNi<sub>3</sub> nanoparticles, are transformed in solution and at mild temperatures into Pt<sub>3</sub>Ni nanoframes with surfaces that have three-dimensional molecular accessibility. The Pt-rich edges of the starting PtNi<sub>3</sub> nanoparticles are maintained in the final Pt<sub>3</sub>Ni nanoframes. Both the interior and exterior surfaces of this open framework structure are composed of a Pt-rich skin structure that exhibits enhanced oxygen reduction reaction activity. The Pt<sub>3</sub>Ni nanoframe catalysts achieved a more than 36-fold and 22-fold enhancement in two different measures of catalytic activity (mass and specific activities, respectively) for the oxygen reduction reaction in comparison to state-of-the-art carbon-supported Pt catalysts (Pt/C) during prolonged exposure to reaction conditions. This work is a significant advance towards developing more efficient electrocatalysts for water-splitting reactions and fuel generation. &nbsp;These electrocatalyst structures were applied to the hydrogen evolution reaction (HER), which is the crucial cathodic reaction in water-alkali electrolyzers, which generate hydrogen by splitting water. The HER activity for highly crystalline Pt<sub>3</sub>Ni&ndash;Pt-skin nanoframe surface was enhanced by almost one order of magnitude relative to Pt/C. &nbsp;Utilizing the spontaneous structural evolution of a bimetallic nanoparticle from solid polyhedra to hollow nanoframes with controlled size, structure, and surface composition should be readily applicable to other multimetallic catalysts.</p>{C5F41FC6-55A1-47B1-8B13-8DCE47BFFE60}http://science.energy.gov/ascr/highlights/2015/bes-2015-02-c/Predicting Magnetic Behavior in Copper Oxide Superconductors<img src='/~/media/EB7BD2A057ED4D319D33966C2DF85DC3.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>New theoretical techniques predict experimental observations in superconducting materials.Thu, 26 Feb 2015 16:05:45 -0500<p>Theory has long had difficulty predicting the behavior of transition metal oxides. These materials, combinations of metals such as iron, cobalt, nickel or copper with oxygen, display a wealth of important properties such as magnetism, temperature dependent phase transitions from electrically insulating to conducting, and superconductivity &ndash; a property that allows materials to conduct electricity with perfect efficiency. Accurate theoretical calculations could open the door for discovery of new materials in this class with even better properties than those currently in use. The problem with describing them theoretically is the phenomenon of <em>electron correlation</em>, the fact that the motion of individual electrons depends on the motion of all the others. Theories that treat electron correlation have been known for a number of years but required orders of magnitude greater computer resources than were available. In this research, accurate calculations of magnetic energies were performed at the ORNL leadership class computer for calcium copper oxide (Ca<sub>2</sub>CuO<sub>3</sub>) a material containing nearly one-dimensional (1D) chains of copper, a one-dimensional counterpart of the famous high temperature superconducting cuprates. Like other cuprates the pure material is a magnetic insulator but becomes superconducting with changes in composition &ndash; in this case by increasing the oxygen concentration. Standard theory predicts the pure material (and other cuprates) to be a metal in contrast to the experiments. In this research, the 1D character of the materials permitted detailed comparison between theory and experiments, and showed good agreement between the theoretical data and those obtained from neutron scattering and magnetic susceptibility measurements. The research used highly accurate Quantum Monte Carlo (QMC) calculations. QMC methods accurately describe many-body systems, but at a high computational cost. High-performance computers, such as those at the Oak Ridge Leadership Computing Facility, allow application of QMC to problems that have remained unsolved for decades.&nbsp;This achievement could lead to better predictions of superconductor behavior derived from fundamental laws of physics.</p>{17945220-D424-45E9-A4B2-97EC739C05FD}http://science.energy.gov/ascr/highlights/2014/ber-2014-07-e/Greenland Ice Sheet “Sliding” a Small Contributor to Future Sea-Level Rise<img src='/~/media/C0518B2777784B7C89B88C6A3C497457.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Modeling experiments assess impacts of key melting behavior.Fri, 01 Aug 2014 13:19:53 -0400<p>A wide range of observations suggests that water generated by melt at the ice sheet surface reaches the bed by both fracture and drainage through moulins (roughly circular, vertical to nearly vertical well-like shafts within a glacier through which water enters from the surface). However, these observations are insufficient to determine whether the water enhances ice flow. The research team performed a modeling analysis, varying flow formulations to find two contrasting possibilities: continuously increasing or bounded changes in lubrication and glacier speed with increased meltwater input. These contrasting scenarios were applied to four sophisticated ice sheet models in a series of experiments for a warmer future scenario, forced by likely changes in ice sheet surface mass, lubrication, and a combination of these. The team determined that additional sea-level rise resulting from lubrication is small (&le;8 mm) in comparison with that from experiments forced only by changes in surface mass balance (~170 mm). Although changes in lubrication generate widespread effects on ice sheet flow and form, they do not substantially affect net mass loss.</p>{B50AB03B-6D60-4795-AD8E-938C6DACA53A}http://science.energy.gov/ascr/highlights/2014/np-2014-05-e/Streamlining the Nuclear Force<img src='/~/media/8367204A141A4858A59E948E5E5E1CD3.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>An optimized nuclear force model yields a high-precision interaction with an unexpected descriptive power.Wed, 21 May 2014 14:10:08 -0400<p>&ldquo;Less pain and more gain&rdquo; is the optimistic perspective from a new model of the nuclear interaction. This interaction was systematically derived using the powerful tools of effective field theory. Such a description preserves the symmetries of the underlying theory of the strong nuclear force, quantum chromodynamics (QCD), while enabling calculations of the properties of medium mass nuclei. In the past decade, models of the strong force that resulted from this procedure pointed to the need to include three-body forces for an accurate description of nuclear properties. More recently, nuclear physics theoreticians revisited these models and used state-of-the-art optimization methods to construct a high-precision potential with only two-body interactions. They showed that certain key aspects of atomic nuclei might be understood with two-nucleon forces alone. The new model requires less computational resources than the previous models and indeed poses the question whether more scientific gain is possible with less computational pain.</p>{697C60A0-0722-4AF5-9939-793903BCD9B3}http://science.energy.gov/ascr/highlights/2013/np-2013-06-a/Supercomputing on a Budget<img src='/~/media/F04183EAA05E4ABCAC65FCEF4DF39D51.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>The optimization of commercial hardware and specialized software enables cost-effective supercomputing.Mon, 27 Jan 2014 09:44:16 -0500<p>Nuclear physicists are building compute clusters that offer supercomputer-style performance without the supercomputer-style price tag. With software designed at Jefferson Lab and partner institutions, computer scientists and physicists are using NVIDIA K20 GPUs (graphics processing units), Intel Xeon Phi accelerator cards and high-speed network connections of up to 56 gigabits per second to create computing systems that are up to ten times more cost effective than conventional systems. The newest clusters&mdash;deployed in late 2012 with cards of over 1 teraflop, double precision performance and four cards per server&mdash;expand the range of applications that can be tackled. Jefferson Lab is now running a total of 776 compute accelerators in 220 servers, with a performance of over 150 teraflops on key science kernels. The new GPUs exhibit a marked improvement in performance over un-accelerated systems in benchmark calculations using a framework for theory calculations developed at Jefferson Lab called Chroma, along with a library of highly optimized routines called QUDA, developed primarily by NVIDIA and a larger developer community that includes Jefferson Lab. Since the first NVIDIA GPUs were deployed at Jefferson Lab in 2009, code developers at the laboratory and NVIDIA have worked in partnership to ensure that Chroma and QUDA harness their full capabilities for science. Following optimization, Chroma and QUDA ran three times faster on last-generation GPUs in performance tests; when the code was tested on the newer NIVIDIA K20 GPUs, it ran a total of six times faster. This success in creating software suitable for heterogeneous computing has the potential for producing benefits in other areas of scientific computing, from biology to oceanography. Initial code developments for the Xeon Phi systems, developed in close collaboration with Intel Parallel Labs, also show excellent performance of up to 300 gigaflops on a single device in single precision, indicating a great potential for this new architecture.</p>{B8B947B0-62E8-4BE7-91CF-D60B69404801}http://science.energy.gov/ascr/highlights/2013/hep-2013-04-a/How Accelerator Physicists Save Time<img src='/~/media/6517788EDC124DFE84A927325F940161.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>A boosted frame of reference boosts the speed of calculations.Fri, 06 Dec 2013 12:52:49 -0500<p>Accelerator physicists lean heavily on simulations to model complicated systems in order to better understand them. Through a novel technique, physicists at Lawrence Berkeley National Laboratory have significantly reduced the computation time for the modeling of plasma wakefield acceleration, a technique that may lead to the development of next-generation high energy accelerators.&nbsp; Imagine a meter-long beam pipe filled with a pre-ionized gas (i.e. a plasma) down which a single laser pulse and an electron bunch are sent. The pulse produces a periodically varying electric field&mdash;a wakefield--in the plasma trailing behind it that can be used to accelerate those electrons. As the pulse, electron bunch, and wakefield propagate along the length of the beam pipe they evolve due to their self-interactions and interactions with each other. The physicist&rsquo;s goal is to understand how the energy of the electrons can be maximized without degrading their bunching. The traditional way to model the laser pulse transitting the beam pipe would be in discrete time steps. &nbsp;Unfortunately this approach is extraordinarily computationally intense.&nbsp; In a new approach, LBNL scientists shifted the frame of reference (called a Lorentz transformation) from the lab to the wakefield, a &ldquo;boosted frame&rdquo; in which the lab frame is moving near the speed of light. The relativistic effect of time dilation means that the evolution of the plasma electrons slows down relative to the electron bunch and laser pulse. Whereas in the lab frame millions of time steps are required for the calculation, thus leading to lengthy computation times, only hundreds of time steps are required in the boosted frame, providing a much better tool for these simulations.</p>{CD885EE5-3074-41D0-B6F3-490A256402B6}http://science.energy.gov/ascr/highlights/2013/bes-2013-04-c/Discovery of New Materials to Capture Methane<img src='/~/media/3B2FE2C9F1C444738FAE5C7CC1F074B7.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Predicted materials could economically produce high-purity methane from natural gas systems and separate methane from coal mine ventilation systems.Fri, 06 Dec 2013 13:26:26 -0500<p>Methane, a common gas emitted from natural gas systems, landfills, coal mining, waste water treatment and hydrates in the ocean, is both a great energy source and a greenhouse gas with a global warming potential over 20 times that of carbon dioxide (CO<sub>2</sub>). Methane often coexists with CO<sub>2</sub> and nitrogen gas (N<sub>2</sub>). Effective techniques are badly needed for the economical separation of methane from these gases to use methane as a fuel and to reduce its environmental impact. However, this has proved challenging because methane molecules are nonpolar, that is, an overall charge-neutral system with a highly symmetric structure that makes it interact weakly with most materials systems. To address this knowledge gap, a team of scientists from the Center for Gas Separations Relevant to Clean Energy Technologies EFRC at Lawrence Berkeley National Laboratory collaborated with scientists at Lawrence Livermore National Laboratories to develop novel computational approaches to screen over 87,000 possible zeolites (porous crystalline adsorbents used by oil industries). This study discovered a few zeolite structures that are technologically promising &ndash; they have both sufficient methane sorption capacity and excellent selectivity for the separation of methane from mixtures with CO<sub>2</sub> and/or N<sub>2</sub>. Realization of these new materials could enable natural gas industries to economically produce high purity methane from natural gas systems and could be used to separate methane from a variety of low concentration sources to reduce methane&rsquo;s environmental impact and enhance safety in closed environments in which high methane concentrations could result in explosions.</p>{1967A065-3ADA-4E22-A1E9-D749CDEE4B15}http://science.energy.gov/ascr/highlights/2013/bes-2013-03-c/Understanding How Semiconductors Absorb Light<img src='/~/media/9F25FEE77D5148C6A1B3D470A4D64172.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Advances in how we calculate optical properties of semiconductors shorten the path to improved solar cells and other optoelectronic devices.Fri, 06 Dec 2013 12:52:49 -0500<p>In semiconductors, light absorption creates energetic electrons and electron vacancies or holes, which can roam freely and in solar cells generate an electric current. In some cases, an electron recombines with a hole to create an exciton &ndash; a charge-neutral state with a spatial extent many times the atomic spacing. Because exciton formation reduces the photocurrent, understanding the size and binding energy of the exciton is important for optimizing the cell&rsquo;s efficiency. Standard theory is not accurate enough to predict exciton properties because they depend on the electrical attraction between a negatively charged electron and a positively charged hole, as well as on the complex reorganization of the surrounding electrons in response to the charge. The new approach from the Colorado School of Mines in collaboration with the National Renewable Energy Laboratory, which combines a &ldquo;many-electron&rdquo; treatment with a description of the spatial extent of the exciton, provides a shorter route to the optimization of performance than experiment alone. The theory gives excellent agreement with experiment for known semiconductors such as silicon, gallium arsenide, and zinc oxide and provides an explanation for the large binding energy in zinc oxide that had previously puzzled researchers.</p>{399347DD-5EA6-4C8C-BE0B-D281D1BE0DF4}http://science.energy.gov/ascr/highlights/2013/bes-2013-02-c/Understanding Nature’s Choreography in Batteries<img src='/~/media/214E9D85FBC64973AC4D23F2E487EF31.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Charge-discharge chemistry for lithium ion batteries elucidated by theoretical calculations.Fri, 06 Dec 2013 12:52:50 -0500<p>Ethylene carbonate (EC) electrolytes and manganese spinel (Li<sub>x</sub>Mn<sub>2</sub>O<sub>4</sub>) positive electrodes are commonly used in lithium ion batteries.&nbsp;A comparison of the electrochemical potentials of EC and bulk Li<sub>x</sub>Mn<sub>2</sub>O<sub>4</sub> suggests that decomposition of the electrolyte would not occur directly by electrons being transferred from EC to the electrode material, but the surface of a solid can have very different properties than its interior bulk.&nbsp;Researchers at Sandia National Laboratories, as part of the Nanostructures for Electrical Energy Storage (NEES) EFRC, have completed detailed coupled simulations of the molecules of the electrolyte and the surface of the positive electrode showing that the oxygen atoms on a Li<sub>0.6</sub>Mn<sub>2</sub>O<sub>4</sub> surface can deform and weakly bind the EC molecule when it is near the electrode surface. This initial interaction does not involve the transfer of electrons (i.e., oxidation) but does enable breaking of the carbon-oxygen bond and subsequent molecular rearrangements that result in two electrons and a proton being transferred to the electrode surface.&nbsp; Therefore, a predicted series of five steps breaks down the electrolyte molecule, leaving the oxidized EC fragment still bound to the now acidified electrode surface.&nbsp; Acidification of positive electrodes is widely believed to initiate corrosion of the electrode surface and possible dissolution of manganese atoms.&nbsp;The proposed acidification mechanism&nbsp;illustrates the importance of modeling the electrolyte and the electrode surface together.</p>{55CEF659-B461-4369-AA05-8AB2E8BFEF23}http://science.energy.gov/ascr/highlights/2012/ascr-2012-10-a/“Dark Fiber” Enables Research to Create Tomorrow’s Internet<img src='/~/media/ascr/images/highlights/2012/10/100g-sim-thumb.jpg' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>The Advanced Networking Initiative testbed is allowing researchers to develop radical new technologies for the next generation Internet.Fri, 10 May 2013 16:35:48 -0400
<p>The 100 Gbps dark fiber testbed provides a facility for researchers to address the challenges of deploying and operating high speed optical networks. This includes research into disruptive technologies and approaches that are not ready to mingle with production traffic. “Just because the network is 10 times faster does not mean the protocols and middleware will be 10 times faster,” said Brian Tierney of the Energy Science network (ESnet). Such discrepancies could create bottlenecks that slow down the network, frustrating fulfillment of its potential. The testbed, which is open to industry, government labs and academia, allows a user project to be the only traffic on the testbed, enabling experiments in a truly controlled environment. One of the challenges in network research is repeatability, so giving a researcher complete control of a 100 Gbps testbed allows the experiment to be re-run multiple times, enabling them to adjust the experiment if needed, leading to more exact results. For the networking research community, there is no other test environment like this that provides researchers the ability to experiment with their ideas “at scale” on a national backbone. And none of the U.S. research groups in industry or academia could afford to build an environment like this on their own. Eric Dube, Senior Product Manager of Systems at Bay Microsystems, Inc., stated “This is the first time Remote Direct Memory Access (RDMA) over distance has been proven to work at full bandwidth for 40 Gbps data rates. Gaining access to a 40 Gbps wide area optical circuit is very costly and had prohibited this kind of research in the past. Using the ANI testbed, we are now able to prove these concepts in a live network environment setting the stage for deploying scalable RDMA-enabled applications over 100G networks. This is especially important as more geographically dispersed data centers and science sites will require this type of bandwidth and capability.” </p>
{4C9F237A-9310-40D9-BC5F-BB7C8AAA8212}http://science.energy.gov/ascr/highlights/2012/ascr-2012-10-b/Universe in a (Blue) Bottle<img src='/~/media/ascr/images/highlights/2012/10/91212-supercomputer-universe-thumb.jpg' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Simulating the evolution of the universe on the Argonne Leadership Computing Facility’s IBM Blue Gene/Q.Mon, 18 Mar 2013 10:33:10 -0400
<p>Cosmology—the science of the origin and development of the universe—is entering one of its most scientifically exciting phases. Two decades of surveying the sky have culminated in the celebrated Cosmological Standard Model. While the model describes current observations to accuracies of several percent, two of its key pillars, dark matter and dark energy—together accounting for 95% of the mass energy of the universe—remain mysterious. Scientists would love to be able to rewind the universe and watch what happened from the start. Since that's not possible, researchers must create their own mini-universes inside computers and unleash the laws of physics on them, to study their evolution. Using the Argonne Leadership Computing Facility’s IBM Blue Gene/Q, researchers have simulated the evolution of the universe through the first 13 billion years after the big bang. The simulation tracks the movement of trillions of particles as they collide and interact with each other, forming structures that transform into galaxies. This simulation is part of a project led by physicists Salman Habib and Katrin Heitmann of Illinois' Argonne National Laboratory resolving galaxy-scale mass concentrations over observational volumes representative of state-of-the-art sky surveys. This initiative targets an approximately two- to three-orders-of-magnitude improvement over currently available resources. The simulation is based on the new HACC (Hardware/Hybrid Accelerated Cosmology Code) framework aimed at exploiting emerging supercomputer architectures such as the IBM Blue Gene/Q at the ALCF. HACC is the first (and currently the only) large-scale cosmology code suite worldwide that can run at this scale and beyond on all available supercomputer architectures. To achieve this versatility, the researchers had to build the code from scratch working closely with advanced computing researchers. One of the main mysteries they hope to solve with the simulations is the origin of the dark energy that's causing the universe to accelerate in its expansion.</p>
{58B28D5A-2CEB-42AC-ACEB-21738879AB51}http://science.energy.gov/ascr/highlights/2012/ascr-2012-10-c/Designing Drugs on Supercomputers<img src='/~/media/ascr/images/highlights/2012/10/baudry-thumb.jpg' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Researchers use Oak Ridge Leadership Computing Facility to accelerate drug discovery.Fri, 15 Mar 2013 17:37:58 -0400
<p>Jerome Baudry, an assistant professor at the University of Tennessee (UT) and member of the Center for Molecular Biophysics at Oak Ridge National Laboratory (ORNL) and his team of computational biophysicists use supercomputers much like other scientists use microscopes. After making alterations to publicly licensed software from the Scripps Research Institute, they were able to create 3D biological simulations of compounds docking with receptors in the body and run it on one of the world’s fastest computers to screen millions of candidates in a few days. The simulations the team created are based upon the process by which molecular compounds function within the body. Pharmaceuticals work because they bind specifically to certain cellular receptors that play roles in health and disease; similar to the way a key fits a lock. When that key opens too many locks, however, side effects occur. Baudry and his collaborators want to be able to predict the specific binding of a drug to a receptor to avoid cross-reactivity. Knowing this behavior will help researchers generate drug candidates likely to survive clinical trials. Thanks to the efficient and massive computations possible using the Oak Ridge Leadership Computing Facility, Baudry and his collaborators can screen drug candidates against multiple receptors and the dynamic structural variations of those receptors. The ability to run simulations greatly reduces the sample size as poor drug candidates get eliminated and ultimately produces a more specifically binding, and therefore more efficient, drug.</p>
{2E5A8E94-748F-4C47-A217-35D56E87E8BD}http://science.energy.gov/ascr/highlights/2012/bes-2012-08-a/New Superhard Form of Carbon Dents Diamond<img src='/~/media/A7C71133E9E44C73BDB4C360EDFEF132.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Squeezing creates new class of material built from clusters of carbon atoms.Fri, 10 May 2013 16:44:22 -0400<p>How do you dent diamond, one of the Earth&rsquo;s hardest materials? Researchers supported by the Energy Frontier Research in Extreme Environments EFRC&nbsp;created a new substance that can do just that. To make the new material, the researchers started with &lsquo;buckyballs,&rsquo; soccer-ball shaped cages composed of sixty carbons, and mixed them in a liquid solvent called xylene.&nbsp; The molecules of xylene served to &ldquo;link&rdquo; the buckyballs together in a regular, crystalline pattern like beads on a string. Finally, they squeezed the mixture in a diamond anvil cell in-situ in the synchrotron beam of the Advanced Photon Source. &nbsp; Something extraordinary happened around 320,000 times atmospheric pressure; the buckyballs collapsed and formed disordered, amorphous clusters but the xylene molecules held fast and still tethered the amorphous pieces together in a pattern like before. The resulting, never-before-seen structure was surprisingly hard; strong enough to dent the diamond anvil. The material stayed in the same structure even after the pressure had been released, which makes it potentially useful for a variety of different devices, especially future electronics. (<a href="/news/featured-articles/2012/08-27-12/">Excerpt from DOE-SC's "In&nbsp;Focus"</a>)</p>{F4D603E0-21F6-45BF-976C-0CA60BF307B0}http://science.energy.gov/ascr/highlights/2012/bes-2012-07-b/Underground Storage of Carbon Dioxide&mdash;as a Solid <img src='/~/media/34DCFCF74E5649CDA7424992D2865AA9.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Nanoscale features in rocks enable more carbon dioxide to be trapped as a solid carbonate material underground.Fri, 10 May 2013 16:35:00 -0400<p>Advanced experiments and computations have shown that underground carbonate mineral nucleation and growth is strongly dependent on nanoscale features such as the pore structure and surface topography of permeable rocks and the interfacial energies between rock surfaces and solid carbonates. This research at the Lawrence Berkeley National Laboratory&rsquo;s Center for Nanoscale Control of Geologic CO<sub>2</sub>, Washington University in St. Louis, and Oregon State University provides the quantitative parameters necessary to develop advanced models that describe how nucleation and growth of carbonate occur in porous media that contain multiple minerals with different surface properties and micro- to nanoscale pores. In carbon capture and storage, CO<sub>2</sub> is captured from power plant exhaust and other sources and injected underground into porous rock formations where it mixes with ambient salt water and may remain for 1000&rsquo;s of years. Although it is expected that CO<sub>2</sub> can be transformed to carbonate minerals, it is unknown how fast this will occur and how the addition of new carbonate mineral in the rock formations will affect the short and long-term behavior of the system. This research will enable more realistic modeling of mineral formation from the injected CO<sub>2</sub> and thus increase the pace of deployment of this critical energy technology.</p>{827B7490-9130-45F4-9738-7AA505E6863D}http://science.energy.gov/ascr/highlights/2012/ascr-2012-06-a/Supercomputers Drive Discovery of Materials for More Efficient Carbon Capture<img src='/~/media/ascr/images/highlights/2012/06/gtoc-thumb.jpg' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>Researchers use NERSC to Create Carbon Dioxide-Separating Polymer.Fri, 10 May 2013 16:35:53 -0400
<p>Using supercomputers at the Department of Energy’s National Energy Research Scientific Computing Center (NERSC), researchers from Haverford College have come up with a new type of two-dimensional polymer, PG-ES1, which allows, in theory, for highly efficient separation of carbon dioxide. Based on simulations, PG-ES1 is predicted to be more than 100-times as permeable to carbon dioxide than the best existing materials, while maintaining a rejection of nitrogen and methane gases that meets or exceeds the best existing materials. This allows it to act as a molecular filter that lets the carbon dioxide to pass through easily, while preventing other gases from escaping. Haverford Assistant Professor of Chemistry Joshua Schrier authored a paper on this new material in the most recent issue of ACS Applied Materials and Interfaces. He says the key to the new process is to utilize both the preferential adsorption of carbon dioxide gas molecules on the surface and the ability to create small, nanometer-sized pores in the surface. “Nitrogen and carbon dioxide are linear molecules, and the holes are too small to allow them to enter in any way other than along their ‘skinniest’ dimensions,” says Schrier. “As it turns out, carbon dioxide is a little skinnier than nitrogen, which allows it to pass through the hole more readily. Although it is unlikely that a random molecule would have the correct orientation, the surface adsorption helps increase the local concentration of carbon dioxide and allows each carbon dioxide molecule to try several attempts at different orientations until it finds the correct one, which ‘stacks the deck’ in favor of carbon dioxide passage. Nobody has previously considered the role of surface adsorption on the barrier crossing process, but it is absolutely crucial for performing this type of separation.”</p>
{A5BC3BF9-BFDA-4030-81B9-C06A32DC58E7}http://science.energy.gov/ascr/highlights/2012/ascr-2012-04-a/Water, Water, Everywhere<img src='/~/media/ascr/images/highlights/2012/04/desal-thumb.jpg' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>NERSC helps researchers design new desalination technology.Fri, 10 May 2013 16:35:31 -0400
<p>Guided by advanced molecular modeling at the National Energy Research Supercomputing Center, Massachusetts Institute of Technology scientists are investigating how to turn atom-thick carbon layers into membranes for a new and improved desalination method in places with inadequate fresh water. “Without any actual experimental demonstration, what our calculations tell us is that the performance of the graphene membrane for water desalination would be very high,” says Jeffrey Grossman, a materials scientist who is MIT’s Carl Richard Soderberg, associate professor of power engineering and leader of the investigation. Graphene, first described in 1962 and the focus of a 2010 Nobel Prize in physics, is a chicken-wire mesh of carbon atoms that provide the underpinnings for graphite, charcoal, carbon nanotubes and buckyballs. What has sparked Grossman’s group’s interest is graphene’s phenomenal structural strength and chemical attributes that might make it ideal for filtering salt from seawater. The goal is to drill just-the-right-width, billionth-of-a-meter nanopores into graphene’s normally impenetrable surface so pressurized water alone could get through without damaging the ultrathin structure. That might make it more efficient than the reverse osmosis process that now offers the best performance of all seawater desalination options. The problem is reverse osmosis has comparatively high costs and energy use. Those faults mean that although seawater is widely available, “dramatically new technologies” are needed to make desalination “a sustainable water supply option,” Grossman and graduate student David Cohen-Tanugi reported earlier this year in the journal Nano Letters. Computer modeling is increasingly essential to modern-day chemistry and materials science because, according to Grossman “it sits in between theory and experiment,” so that “we can do actually what an experiment would have a hard time doing, which is to peel away the levels of complexity one by one.”</p>
{8BC06A67-DEDD-458E-9B53-E9776408E7D6}http://science.energy.gov/ascr/highlights/2011/bes-2011-10-a/Graphene-based Electrode Leads to Highest Capacity Lithium-Air Batteries<img src='/~/media/C7E27545603146E2977E778E78BB1B79.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/>New approach to molecular self-assembly produces porous, thin films of carbon (aka graphene), enabling high-capacity electrodes for lithium-air batteries.Fri, 30 Aug 2013 14:51:06 -0400<p>Graphene, a molecularly thin sheet of carbon, is among the most interesting new materials being developed to achieve revolutionary, high-performance batteries needed for the electrical grid, electric cars, and other types of energy storage. In research at Pacific Northwest National Laboratory and Princeton University, a new way to control the 3D porous architecture and reactive surfaces of graphene has been discovered. By employing self-assembly at the oil-water interface in oil-water emulsions, an unusual hierarchical arrangement of functionalized graphene sheets has been achieved. This material when used as an air electrode delivers an exceptionally high capacity of 15,000 mAh/g in lithium-air batteries, the highest value ever reported. This excellent performance is shown to be due to the presence of two types of pore structures in the electrode material&mdash;micron scale pores for facilitating rapid air (oxygen) diffusion and nanoscale pores with a high density of reactive sites for lithium-oxygen reactions. The hierarchically ordered porous structure also enables high storage capacity by promoting accessibility to most graphene sheets in the structure, and a patent application has been filed.</p>